Load cells are among a number of electro-mechanical transducers that may be used to sense a force exerted by a load, such as, for example, a beam, upon a target object. A load cell may be used to sense the force by first coupling a movable sensing portion of the load cell, which may be referred to as “a sensing node,” to the target object, and coupling a base portion of the load cell, which may be referred to as “a base,” to a fixed, non-movable reference point, e.g., a system chassis. After the force is applied to the target object, and thus to the sensing node, flexible components of the load cell, which may be referred to as “sensing beams,” that couple the sensing node to the base and make the sensing node movable with respect to the base, may deform in response to the applied force. For example, the sensing beams may deform by an amount that is proportional to the applied force.
Subsequently, deformation sensors, e.g., strain gages (sometimes referred to as strain “gauges”), disposed on the sensing beams, in conjunction with associated electrical bias and conditioning circuitry, may transform the deformations of the sensing beams into electrical signals indicative of the deformations, and output the signals as a representation of a magnitude of the force applied to the target object. For example, the strain gages may be arranged in a commonly used Wheatstone-Bridge configuration. Additionally, in some examples, the sensing beams may be oriented within the load cell in such a manner that allows a particular subset of the sensing beams to deform in response to a particular component of the applied force, and to not substantially deform in response to all other components of the force. For example, multiple subsets of the sensing beams may be configured within the load cell in this manner, such that each of the subsets of the sensing beams deforms in response to a different component of the applied force. In this manner, the load cell may be used to sense not only an overall magnitude of the force applied to the target object, but also a magnitude of each of one or more components of the force that correspond to particular directions with respect to the target object, and, therefore, the load cell. Sensing force in the manner described above may be useful in a variety of applications, including, for example, measurement and calibration, process control, and manufacturing applications, as some examples.
Existing load cells are generally configured to sense force in one or two directions, namely, in one or more of an X-direction and a Y-direction, relative to a particular load cell. Such load cells may be referred to as “low-profile” load cells, since the sensing beams used to sense the force in the one or two directions may be arranged in a low-profile plane (e.g., the X-Y plane) within each load cell. In order to sense force in additional directions, e.g., in the Z-direction, multiple load cells may be combined within a given force sensing application. Alternatively, a more complex “high-profile” load cell may be used that employs additional sensing beams disposed outside of (e.g., perpendicular with respect to) the low-profile plane and configured to deform in response to a component of the force that corresponds to each of the additional directions. Accordingly, existing techniques for using load cells to sense force in more than two directions relative to a target object may require using multiple “low-profile” load cells each configured to sense force in up to two directions, or a single more complex “high-profile” load cell configured to individually sense force in more than two directions.